RESUMEN
Anal intraepithelial lesions (ASILs) are considered as precursors of anal cancer. The incidence of high-grade ASIL (HSIL) and progression of low-grade ASIL (LSIL) to HSIL are high in HIV-positive men. Endogenous cytokines, such as interferons (IFNs) play an important role in the regulation of proliferation and immune responses in epithelial cells, and thus, they might control the above-mentioned progression events. Accordingly, we determined mRNA levels of IFN-gamma and IFN-gamma receptors, levels of IFN-gamma receptor-associated kinases (JAK1 and TYK2) and signalling molecules (signal transducer and activator of transcription-1 [STAT1], STAT3, interferon-responsive-factor-1 [IRF-1] and IRF-2) as well as inhibitors of cytokine signalling (protein inhibitor of activated STAT1 [PIAS1] and suppressor of cytokine signalling 2 [SOCS2]) in biopsies of anal condylomas, LSILs as well as HSILs from HIV-positive individuals by a semi-quantitative reverse transcribed polymerase chain reaction (RT-PCR) method. We found that HSIL significantly differs in expression of these genes from LSIL and condylomas. Expression profile of HSIL samples showed activation of STAT3 signalling, probably accounting for the observed high levels of genes that support cellular proliferation (IRF-2, c-fos and c-myc). Decreases in levels of suppressors (IFN-gamma and IRF-1) and JAK1 kinase, but increases in levels of inhibitors of cytokine signalling (PIAS1 and SOCS2) might also contribute to the altered cytokine signalling in HSIL biopsies. These findings might reveal important molecular events associated with progression of LSIL to HSIL in HIV-infected men.
Asunto(s)
Neoplasias del Ano/inmunología , Condiloma Acuminado/inmunología , Seropositividad para VIH/complicaciones , Interferón gamma/inmunología , Neoplasias de Células Escamosas/inmunología , Lesiones Precancerosas/inmunología , Canal Anal/patología , Enfermedades del Ano/inmunología , Enfermedades del Ano/patología , Neoplasias del Ano/patología , Biopsia , Condiloma Acuminado/patología , Progresión de la Enfermedad , Expresión Génica , Humanos , Interferón gamma/genética , Neoplasias de Células Escamosas/patología , Fosfotransferasas/análisis , Fosfotransferasas/genética , Lesiones Precancerosas/patología , ARN Mensajero/análisis , Receptores de Interferón/genética , Receptores de Interferón/inmunología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de SeñalRESUMEN
BACKGROUND: The incidence of anal high-grade intraepithelial lesions (HSILs) and progression of anal low-grade intraepithelial lesions (LSILs) to HSIL are high in HIV-positive men. Endogenous cytokines might support the pathogenesis of this progression. MATERIALS AND METHODS: Accordingly, we determined mRNA levels of IL-6 and TNF alpha and their receptors together with viral genes (HIV-gag and HPV E7) in biopsies of anal condylomas, LSILs and HSILs from HIV-positive individuals by a semiquantitative RT-PCR method. RESULTS: We found that HSIL significantly differs in expression of these genes from LSIL and condylomas, and the latter two lesions were virtually undistinguishable from each other. A correlation between cytokine levels and HIV as well as HPV E7 transcripts suggests that changes might be associated with each other. CONCLUSIONS: These findings reveal important molecular events associated with progression of anal intraepithelial lesions (ASILs) in HIV-infected men.
Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA , Neoplasias del Ano , Condiloma Acuminado , Seropositividad para VIH/complicaciones , Interleucina-6/biosíntesis , Neoplasias de Células Escamosas , Factor de Necrosis Tumoral alfa/biosíntesis , Infecciones Oportunistas Relacionadas con el SIDA/complicaciones , Infecciones Oportunistas Relacionadas con el SIDA/metabolismo , Infecciones Oportunistas Relacionadas con el SIDA/patología , Infecciones Oportunistas Relacionadas con el SIDA/virología , Neoplasias del Ano/complicaciones , Neoplasias del Ano/metabolismo , Neoplasias del Ano/patología , Neoplasias del Ano/virología , Condiloma Acuminado/complicaciones , Condiloma Acuminado/metabolismo , Condiloma Acuminado/patología , Condiloma Acuminado/virología , Progresión de la Enfermedad , Proteína p24 del Núcleo del VIH/biosíntesis , Proteína p24 del Núcleo del VIH/genética , Seropositividad para VIH/virología , Humanos , Interleucina-6/genética , Neoplasias de Células Escamosas/complicaciones , Neoplasias de Células Escamosas/metabolismo , Neoplasias de Células Escamosas/patología , Neoplasias de Células Escamosas/virología , Proteínas Oncogénicas Virales/biosíntesis , Proteínas Oncogénicas Virales/genética , Papillomaviridae/aislamiento & purificación , ARN Mensajero/biosíntesis , ARN Viral/biosíntesis , Receptores de Interleucina-6/biosíntesis , Receptores de Interleucina-6/genética , Receptores del Factor de Necrosis Tumoral/biosíntesis , Receptores del Factor de Necrosis Tumoral/genética , Factor de Necrosis Tumoral alfa/genéticaRESUMEN
We hypothesized that measurement of a specific product from reaction of N,N'-dimethylthiourea (Me2TU) and H2O2 would provide a good indication of the H2O2 scavenging and protection seen after addition of Me2TU to biological systems. We found that addition of H2O2 to Me2TU yielded a single stable product, Me2TU dioxide. Me2TU dioxide formation correlated with Me2TU consumption as a function of added H2O2 concentration and was prevented by simultaneous addition of catalase (but not boiled catalase), superoxide dismutase, dimethyl sulfoxide, mannitol, or sodium benzoate. Me2TU dioxide formation, Me2TU consumption, and H2O2 concentration increases occurred in mixtures containing phorbol 12-myristate 13-acetate (PMA) and normal human neutrophils but not in mixtures containing PMA and neutrophils from patients with chronic granulomatous disease or in mixtures containing PMA and normal neutrophils and catalase. Me2TU dioxide formation also occurred in isolated rat lungs perfused with Me2TU and H2O2 but not in lungs perfused with Me2TU and elastase, histamine, or oleic acid. In contrast, Me2TU dioxide formation did not occur after exposure of Me2TU to 60Co-generated hydroxyl radical or hypochlorous acid in the presence of catalase. The results indicate that reaction of Me2TU with H2O2 selectively forms Me2TU dioxide and that measuring Me2TU dioxide formation from Me2TU may be useful for assessing the presence and significance of H2O2 in biological systems.
Asunto(s)
Peróxido de Hidrógeno/análisis , Neutrófilos/fisiología , Tiourea/análogos & derivados , Animales , Cromatografía de Gases , Cromatografía Líquida de Alta Presión , Edema , Enfermedad Granulomatosa Crónica/sangre , Humanos , Peróxido de Hidrógeno/sangre , Cinética , Pulmón/patología , Neutrófilos/efectos de los fármacos , Acetato de Tetradecanoilforbol/farmacologíaRESUMEN
Addition of increasing concentrations of hydrogen peroxide (H2O2) caused progressive decreases in dimethylthiourea (DMTU) concentrations which were inhibitable by simultaneous addition of catalase, but not the superoxide anion (O2-.) scavenger, superoxide dismutase (SOD), or hydroxyl radical (.OH) scavengers, such as mannitol, sodium benzoate or dimethyl sulfoxide (DMSO). In parallel, addition of increasing concentrations of H2O2 with FE++/EDTA (but not H2O2 alone) caused decreases in DMSO concentrations which were inhibitable by simultaneous addition of .OH scavengers but not SOD or catalase. Addition of DMTU, but not DMSO, also decreased H2O2 concentrations in vitro. The results indicate the relative scavenging specificities of DMTU and DMSO for H2O2 and .OH, respectively. The findings also suggest that measurement of DMTU or DMSO consumption could help assess the contribution of O2 metabolites in biological systems.